does this exist?
If it does I would love to know, I have been looking for it myself.
I've not seen this in person but their 12X24 porcelain calacatta is very nice IMO. The corresponding bullnose for this style did have some boxes where finish was slightly rougher and not as smooth as the 12X24 - not sure if this applies to the subway version.
I've included the link to Floor and Decor Outlets below. They have been known to run out - mainly because they buy the surplus when the big tile companies eliminate something from their catalog - thus often only have a limited amount (but usually at a good price).
(I'm not connected with them except as a satisfied customer.)
Here is a link that might be useful: Floor and Decor - calacatta porcelain subway